Switching mechanism



Sept. 11, 1934. s. B. SANFORD SWITCHING MECHANISM Original Filed July 30. 1926 FIQI a m T m m T N E m S Patented Sept. 11, 1934 iNfiTED STATES PATENT @i SWETCHING MECHANISM Griginal application July 39, 1926, Serial No. 626,3t3. Divided and this application May 24,

1933, Serial No. 672,612

Claims.

The present invention relates to switching mechanisms, particularly for use in signalling systems for elevator installations and in control systoms for the elevator car.

This application is a division of application Serial No. 626,303, filed July 30, 1926.

The switching mechanism to which the invention relates is of the type having a plurality of stationary contacts, one for each of the various floors served by the car, and movable contacting means, for engaging said stationary contacts, moved with respect to said contacts in accordance with the movement of the car with respect to the floors for which the contacts are provided. Such switching mechanisms are known by various terms in the elevator ndustry, such as selectors, floor controllers and commutators.

It is desirable that such switching mechanism be as compact as possible. However, a considerable number or present day buildings have such a large number of floors requiring stationary contacts on the switching mechanism as to tend to defeat the attainment of this desirability.

One feature of the invention is the provision of such a switching mechanism in which alternate stationary contacts arearranged in staggered relation.

Another feature of the invention is the provision of switching mechanism having movable contacting means effective on two sides and having every other one of the stationary contacts contacting with one of said sides and the other stationary contacts contacting with the other one of said sides.

Other features and advantages will be apparent from the following description and appended claims.

Although this switching mechanism may be operated in various ways, it will be described as operated by an impulse motor which may be controlled by a contactor device located at a remote point, for example in the elevator penthouse. This motor is provided with a plurality of field coils energizable in a certain sequence to cause rotative movement of the armature of the motor to take place, the armature in turn moving the movable contacting means of the switching mechanism. Such arrangement minimizes the number of wires to the switching mechanism from the point of remote control, as explained in the parent application.

In the drawing: Figure 1 is a front view of the switching mech- (Cl. ZOO-15) tion and arrangement of the stationary contacts W of the switching mechanism and their relation to the movable contacting elements, parts being shown in section; and

Figure 5 is a, detail, taken along the line 5-5 WV of Figure 3, illustratin the mounting of the mov able contact strip of the switching mechanism.

Referring to the drawir. the switching mechanism comprises the commutator proper and the driving mechanism therefor. The commutator has two sets of stationary contacts, one set being above the other. The con acts or" each set are arranged in a semi-circle and radially disposed relative to the center. The contacts of the lower set are mounted in a segment 20 and the contacts of the upper set are mounted in a similar segment 21, the segments being of insulating material. For convenience of further description, these segments will hereinafter be referred to as commutator bases.

The lower commutator base 20 is formed with inwardly extending lugs 22. Each of these lugs is provided with a countersunk aperture 23. Screws 24 secure base 20 to a mounting plate 25, these screws extending through apertures 23 into threaded apertures 26 in the mounting plate. Commutator base 20 is also formed with outwardly extending lugs 27. Similar lugs 28 are formed on upper commutator base 21. Lugs 28 are provided with countersunk apertures 30. Screws 31 secure the upper and lower commutator bases together, these screws extending through apertures 30 into threaded bushings 32 moulded into lugs 27. The lugs 27 and 28 are positioned and dimensioned so as to space the upper commutator base from the lower one.

Each of the stationary contacts comprises a brush 33, for example of silver and graphite, slidably arranged within a bushing 34. These bushings are moulded into the commutator bases. A stationary contact is provided for each floor. The stationary contacts mounted on the lower commute-tor base are for odd numbered floors, while those mounted on the upper commutator base are for even numbered floors. The bushings 34 in each base are equally spaced angularly. The

relative positions of the bushings in the upper and lower bases are such as to stagger the stationary contacts of one set with respect to those of the other, as may be seen from Figure 4. Nineteen stationary contacts are illustrated for the upper commutator base and twenty stationary contacts on the lower base. The contacts on each base are spaced nine degrees apart with those of the upper base half way between those of the lower base. Thus, thirty-nine stationary contacts are provided, rendering the commutating mechanism suitable for elevator systems for up to thirty-nine floors.

The brushes engage contacting segments for controlling the circuits for the various floors. The contacting segments are carried by a disc 35 of insulating material mounted for rotation about the center of the semi-circle formed by the stationary contacts. The brushes of the lower set of stationary contacts engage contacting seg-' ments 36 and 37 arranged on the bottom of disc,

35 and concentric therewith. The brushes of the upper set of stationary contacts engage contacting segments 38 and 40 arranged on the top of disc 35 and concentric therewith. The commutator bases are spaced by lugs 27 and 28 suihciently to permit the disc to extend between them with ample clearance. The contacting segments are of a radius commensurate with that of the semi-circle formed by the stationary contacts so as to place the segments in contact with the brushes.

The bushings for the brushes of the stationary contacts are threaded at their outer ends to receive terminal screws 41. Thebrushes are pressed into engagement with the contacting segments by springs 42 arranged within the bushings between the terminal screws and spring seats formed on the brushes. The contacting segments for the two sets of stationary contacts are oppositely disposed on the contact disc 35 and oppositely disposed segments extend slightly less than one hundred and eighty degrees around the periphery of the disc, the disc being formed with arcuate depressions to receive the segments, these depressions being of the same dimensions as the segments so as to present a flush surface.

A contact strip 43 is moulded into the contact disc between adjoining ends of the contacting segments. This strip also contacts with the brushes of the stationary contacts. The porti'on'of the contact strip between the contacting segments extends beyond the sides of the disc. The disc is sloped outwardly on each side from the contacting segments to the contact strip, as illustrated, to prevent the connecting of the strip to the segments by the brushes 33.

A contacting ring A is also mounted on disc 35. This ring is concentric with the contacting segments but is of less diameter. The ring is positioned in the depression 45 formed in the disc and is secured to the disc in any suitable manner as by screws 46. A stationary brush 4? contacts with ring 44. This brush is mounted in an arm 48 of a terminal board 56. This board is. formed with bosses 51 through which screws 52 extend to secure the board to mounting plate 25. These bosses raise the board to permit arm 48 to extend over disc 35. The arm is provided with 'a bush ing 53 into which brush 4'? slidably extends. The brush is pressed into engagement with ring 44 by a spring 54. arranged between the brush and a screw 55 threaded into the outer end of the bushing. The contact strip 43 extends into a slot 56 formed in ring 44 wherein it is secured as by brasing. The ring 44 and brush 4'] form a current feed for the contact strip.

The contacting segments are fed by brushes 57 and 58 slidably mounted in apertures 60 in the upper commutator base. These apertures are arranged in the ends of the base and are slightly more than one hundred and eighty degrees apart. A brush connector 62 is secured over each aperture as by screw 63 threaded into a bushing 64 moulded into the base. The brushes are pressed into engagement with the contacting segments 38 and 40 by springs 65 arranged between the brushes and brush connectors.

Terminal screws 66 are provided in the ends of the brush connectors for connecting brushes 57 and 58 in the system. The brushes are connected to the terminal screws by stranded cable 67 secured to the brushes and extending through slots 68 in the upper commutator base. Brushes 33 are connected in the system by their terminal screws ii. Brush-47 is connected in the system by a terminal screw 70 on the terminal board, this screw being connected to screw 55 by a conducting strip 71.

The disc 35 is driven by the impulse motor by reduction gearing. gearing comprises an inner toothed gear 73 to which disc 35 is secured as by screws '74. This gear is rotatably mounted on a stub shaft '75 secured to mounting plate 25, the gear being provided with a bushing '26 into which the stub shaft extends. The gear is retained on the bushing by means of a'washer 77 and cotter pin 78. A pinion 80 drives gear 73, this pinion being secured to the end of the armature shaft of the impulse motor 81. This shaft extends through plate 25 which forms the top of the housing for the impulse motor.

The details of the impulse motor are not illustrated. However, an arrangement comprising six wound field poles and a four pole unwound armature is suitable. The field coils are connected to terminals 82 on terminal board 50.

It is preferred to provide braking mechanism to movement causes four and one-half degrees of' rotative movement of the disc. The mechanism is set so that when the car is positioned at a floor, contact strip 43 is in engagement with the brush or" the stationary contact for that floor. Thus, each step of rotative movement of disc 35 causes the contact strip to move into engagement with the brush of the next stationary contact. The direction of movement of the disc is the same as that of the armature of the impulse motor.

It is preferred to provide correcting mechanism to insure that the commutating mechanism is maintained in step with the elevator car. The correcting mechanism comprises a pair of stops 85 and 86 on the outer side of disc 35, arm 48 of the terminal board and a stop device secured to the upper commutator base. The stop device comprises a bracket 87 secured by the terminal screw on top of the stationary contact on the upper commutator base for the upper terminal floor, in case of an even number of floors, and on top of the stationary contact on the upper commutator base next above the one on the lower commutator base in case of an odd number of floors. An adjustable stopping member 88 is secured to the bracket. Stop 85 cooperates with arm 48 at the lower terminal floor and stop 86 cooperates with stopping member 88 at the upper terminal floor. If the disc gets behind during up car travel, it will be ahead of the car upon reversal and during succeeding down car travel, and the correction is made at the lower terminal. If the disc gets behind the car during down car travel, it will be ahead of the car upon reversal and during the succeeding up car travel, and the correction is made at the upper terminal. The stopping member 88 has an aperture to receive screw 91 which secures the member to the bracket. The distance of this aperture from one end 92 of the stopping member is such that with this end facing stop 86, correction is made at the floor corresponding to the stationary contact to which the bracket is secured. The distance of the other end 93 of the stopping member from the aperture is such that with this end facing stop 86, correction is made at the next lower floor. Thus, the member is secured to the bracket so that its end 92 faces stop 86 in case of an even number of floors and so that its end 93 faces the stop in case of an odd number of floors. The correcting mechanism is illustrated in Figure 1 as set for a ten floor installation.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In combination; a group of spaced stationcontacts arranged in a row; a second group spaced stationary contacts arranged in another w, the contacts of the second group being positioned between the contacts of the first group; and movable contacting means common to the contacts of both groups for engaging said contacts.

2. In combination; a plurality of spaced stationary contacts arranged in an arc of a circle; movable contacting means for engaging said stationary contacts, said movable contacting means having electrically connected contacting surfaces on opposite sides thereof, every other one of said stationary contacts being positioned to be engaged by the contacting surface of one of said sides of said contacting means and the other stationary contacts being positioned to be engaged by the contacting surface on the other of said sides of said contacting means and being arranged in staggered relation with respect to said every other one of said stationary contacts; and means for rotating said movable contacting means about the center of the circle formed by said stationary contacts.

3. In combination; a plurality of spaced stationary contacts; a pair of spaced movable contacts for engaging said stationary contacts, each stationary contact being of a width sufiicient to bridge said movable contacts; and means for preventing each stationary contact engaging both of said movable contacts at the same time during movement of said movable contacts as the leading one of said movable contacts moves from a position engaging that stationary contact into one of disengagement therefrom.

4. In combination; a plurality of spaced stationary contacts; a pair of spaced movable contacts for engaging said stationary contacts, each stationary contact being of a width su iicient to bridge said movable contacts; and means for mounting said movable contacts for movement with respect to said stationary contacts, said mounting means comprising means for preventing each of said stationary contacts engaging the following one of said movable contacts during movement of said movable contacts until after the disengagement of the leading one of said movable contacts from that stationary contact occurs.

5. In combination; a plurality of spaced stationary contacts; a pair of spaced movable contacts for engaging said stationary contacts; a contact strip between said movable contacts and movable therewith, each stationary contact being of a width sufficient to bridge said contact strip with either of said movable contacts; means for mounting said movable contacts and contact strip for movement with respect to said stationary contacts in opposite directions, said contact strip extending from said mounting means beyond said movable contacts toward said stationary contacts, said mounting means sloping from said movable contacts out to said contact strip whereby bridging of said contact strip with the leading one of said movable contacts during either direction of movement of said movable contacts is prevented; and means for yieldingly maintaining said stationary contacts in engagement with said movable contacts and contact strip.

SELDEN BRADLEY SAVFORD. 

